[67 455 Bird ragtop]

Under what conditions is a lifter bore recommended ?? Cam specs are below. Spring pressures according to Tin Indian who made my heads is 110-120 on the seat. About 300 open.

[Steve C.]

Post number 3

https://forums.maxperformanceinc.com...r+bore+bracing


Your intake lobe has about 161 degrees duration at 0.200" lift and the exhaust about 171


.

[67 455 Bird ragtop]

Thanks Steve. Very good info. I missed that one when I did a search some how.

[RUDOLFSSON]

FYI :

I have a new brace kit out that I'll start advertise/selling here early next month.... Digitized from the 481988 PMD blocks. Each aluminum block has two clamping forces acting on it plus a 360° epoxy bond.. It'll also serve a job of retaining loose valve train parts from hitting the camshaft.


Kris.

( click the pics for a larger copy )

[Scott Stoneburg]

Kris...looks very nice!

[AIR RAM]

Originally Posted by 69GTO

FYI :

I have a new brace kit out that I'll start advertise/selling here early next month.... Digitized from the 481988 PMD blocks. Each aluminum block has two clamping forces acting on it plus a 360° epoxy bond.. It'll also serve a job of retaining loose valve train parts from hitting the camshaft.


Kris.

( click the pics for a larger copy )

Wow... very nice... I like the oil drain back feature you added... at lest that's what those holes on the side appear to be.

what kind of pricing are you looking at?

SPEED SAFE, NICK

[Johnny406]

That is a nice piece(s) Kris! As for the topic and the way I interpreted Ken Keefer (Pontiac Dude) from my recent post, just about any solid roller lifter would wisely benefit (insurance) from a lifter bore brace. The #2 and #6 intake lifter bores are totally unsupported due to the direction of the camshaft rotation (away from the block and towards the center webbing) would benefit from using lifter bore braces. I'm using a Comp 308R (262 @ .50 duration .575 lift) cam for this 428 build and I am using a (used) Butler Mega-Brage just so I don't have to worry or think about it...

[65nss4spdGTO]

All engines should be braced. Pontiac cut corners not following the RAV and SD blocks. It’s not only about the cam profile, but in the event a lifter takes a crap.

Calvin Hill
Hill Performance
708-250-7420

[hgerhardt]

Originally Posted by 69GTO

FYI :

I have a new brace kit out that I'll start advertise/selling here early next month.... Digitized from the 481988 PMD blocks. Each aluminum block has two clamping forces acting on it plus a 360° epoxy bond.. It'll also serve a job of retaining loose valve train parts from hitting the camshaft.


Kris.

Wow, those are beautiful! Do you think there might be an issue with expansion rate difference between aluminum and iron? As complex (and pretty) as the machine work appears to be, these look like an excellent candidate to 3-d print from DMLS-stainless (Direct Metal Laser Sintering). Those would have similar expansion rate as iron and have a nice rough surface for epoxy-bonding.

[RUDOLFSSON]

Thanks for the interest,
this kit will always need some fitting so I’m not sure if 316/17-4 steel will be popular.. I do it the subtractive way as is.
Pontiac Yodas have used aluminum braces for years and poured aluminum in the heads as well w/o expansion issues that I’m aware of.

Final pricing not quite yet out there..


Ps.
Bare in mind that these are modeled after 70’s blocks and blocks will vary.. pre 70’s blocks seem to need more fitting work and they lack material in some areas.

Kris.


Sent from my iPhone using Tapatalk

[Half-Inch Stud]

...and i thought the #2 Exhaust Lifter bore was the worst/only problem.

[Skip Fix]

Pretty slick looking!

[krisr]

Originally Posted by 65nss4spdGTO

All engines should be braced. Pontiac cut corners not following the RAV and SD blocks. It’s not only about the cam profile, but in the event a lifter takes a crap.

Calvin Hill
Hill Performance
708-250-7420

I'm with you on that one Calvin, even if using a relatively mild hydraulic roller. A full SD brace kit doesn't cost much and you'll sleep better at night.

[Old Goat Racer]

Originally Posted by Half-Inch Stud

...and i thought the #2 Exhaust Lifter bore was the worst/only problem.

It is for me. I have a 455 4-bolt main '70 XF block standard bore with a hairline crack in #2 exhaust. That brace mite be the answer.

[janderson]

Originally Posted by 69GTO

FYI :

I have a new brace kit out that I'll start advertise/selling here early next month.... Digitized from the 481988 PMD blocks. Each aluminum block has two clamping forces acting on it plus a 360° epoxy bond.. It'll also serve a job of retaining loose valve train parts from hitting the camshaft.


Kris.

( click the pics for a larger copy )

Interested when it’s released.

[firechicken]

Originally Posted by janderson

Interested when it’s released.

It has been advertised in the perf parts for sale forum already.

http://forums.maxperformanceinc.com/...d.php?t=836832

[janderson]

Originally Posted by firechicken

It has been advertised in the perf parts for sale forum already.

http://forums.maxperformanceinc.com/...d.php?t=836832

Thanks.

[RUDOLFSSON]

Thanks for the interest... I just posted up my new install guide as a huge image bundle down in the ad....

Kris.